A study about the bio-compatibility of Ti–8Ta–3Nb alloys with surface modification

Ti–8Ta–3Nb alloy was prepared in a non-consumable vacuum arc melting and then homogenized at 1050 °C for 24 h. Surface modifications of this alloy were performed by oxidation and alkali treatment in 5.0 M NaOH solution. A porous, thin activated layer of Ti–8Ta–3Nb alloy was grown on the surface after the alkali treatment. In vitro test was performed by immersing the surface-modified specimens in simulated body fluid (SBF). The microstructure changes of the activated surfaces were observed by optical microscopy, SEM, EDS, XPS and TGA. Cytotoxicity tests were performed in MTT assay which treated L929 fibroblast cell culture using indirect methods. Hydroxyapatite was nucleated onto the activated porous surfaces of Ti–8Ta–3Nb during the in vitro test. During the oxidation at temperatures above 700 °C the rate of gain in mass increased rapidly. XRD data showed that the oxide layers which formed on the surfaces of Ti–8Ta–3Nb were mostly composed of TiO2 (rutile) phases. Cytotoxicity test revealed that moderate oxidation treatment lowered cell toxicity.